1. Field of the Invention
The present invention relates generally to fluid pumping systems. In particular, the present invention relates to an oscillating spring valve fluid pumping system.
2. Background of the Invention
Pumping fluid from a flowing source of the fluid (i.e., water from a river) in order to redirect the fluid for other applications, such as irrigation or filling a tank with water, has been the object of a number of pumping systems. However, most systems require the use of an electrical or other type of motor. This requirement limits the use of many systems in areas where electricity is not readily available. Although combustion engines are typically used as an alternative source of power in remote areas, these are relatively expensive, inconvenient to transport, and not always readily available in remote locations. Furthermore, generators cannot operate pumps for extended periods of time without refueling.
Manual pumps (i.e., hand pumps) may also be used in remote areas. Manual pumps are less expensive than those powered by electricity or combustion engines. However, because manual pumps require an operator, they are typically used in one-time-use applications or short-term applications.
Solar powered pumps are also used to partially remedy the above mentioned shortcomings. However, solar powered pumps are not without limitations. For instance, this type of pump is at the mercy of available sunlight and may limit the size of the pump to very small applications. Although the coupling of rechargeable backup battery sources can be used to reduce this limitation, such a system would be relatively expensive and not readily available to most users in remote areas.
As such, there is a need for a pumping system capable of utilizing the pressure head produced by the flowing fluid (i.e., river) to operate the pump and produce an increased pressure head so that the fluid may be redirected for other applications.
According to its major aspects and broadly stated, the present invention is an oscillating spring valve fluid pumping system. The system comprises a housing that encloses a check valve, an inlet and two outlet orifices, and a spring control valve. The system uses the pressure of the flowing fluid against the spring valve and the resulting water hammer as a power source to pump a portion of the fluid. The check valve is located past the inlet and the spring valve is located past the check valve and at a lower elevation. The spring valve closes when pushed up hard enough against the spring by the force of the flowing water; the check valve opens when pushed up. When the flowing water pressure is not great enough to close the spring valve, fluid flows from the pump past the spring valve and through its outlet and back to the fluid stream. When the flowing fluid closes the spring valve, the back pressure opens the check valve and the fluid is expelled through one of the outlets by the pump for use in irrigation, etc. By setting the spring valve to oscillate (somewhat like starting a pendulum of a clock to swinging but with the flowing fluid continually suppling energy to maintain the oscillations), the two valves will then continue to oscillate under pressure from the flowing fluid and will pump fluid from the check valve""s outlet.
The spring control valve alternately opens and closes 180xc2x0 out of phase with the opening and closing of the check valve to produce an outlet pressure head proportional to the water hammer that results when the spring valve closes and backs up the pressure in the housing. More specifically, in an initial state of rest, the spring control valve is in an open position while the check valve is in a closed position. As fluid flows through the system, a predetermined amount of fluid is allowed to pass around the open spring control valve and return to the source stream downstream of the pump inlet. At a predetermined pressure, the spring control valve closes causing the fluid to be redirected through the check valve and thus through the outlet. Instantaneously, as the fluid is redirected, the pressure at the spring valve drops causing the spring control valve disk to spring open thus causing a hammer affect upon the fluid. On the upward return of the spring control valve disk, the fluid is again redirected through the check valve, but at an increased pressure head. Both the spring control valve and the check valve oscillate through this repeating cycle, resulting in a continuous hammering effect on the fluid. Given a flow rate of the stream of fluid and a diameter of the piping, the spring setting on the spring control valve can be adjusted to maximize the outlet pressure head and/or to achieve a predetermined outlet pressure head, preferably, at 80-90 cycles per minute.
In a preferred embodiment, the fluid enters the system through a flared inlet and is directed through a series of elbow joints so that the fluid is flowing in a vertical direction when it contacts the spring control valve and the spring control valve is at approximately the same elevation of the fluid when it enters the flared inlet. This arrangement provides the maximum available force against the horizontal disk of the spring control valve thus facilitating the vertical oscillation of the spring control valve. The spring control valve is positioned vertically so that gravity can be used to open the valve. Additionally, two independently operating springs are used on the spring control valve so that one provides an upward force when the disk is in its lower extended position, and the other provides a downward force when the disk is in the upper closed position for greater control over the frequency of oscillation. The amounts of upward and downward spring force can vary depending on several factors including, fluid flow rate, pipe diameter, horizontal position of the disk relative to the stream of fluid flow at the inlet, and the weight of the spring control valve. However, these variables can be easily compensated for by rotating a set of adjustment nuts to increase or decrease the spring tension.
A feature of the present invention is the alternating opening and closing of the spring control valve and the check valve to produce an outlet pressure head. No motor or other power source is required because the power for the pump comes from the flowing fluid itself harnessed by the springs of the spring valve; nonetheless, with the appropriate spring adjustments, a predetermined increase in pressure head results at the system outlet. Additionally, because the present invention requires no motors and because any unused fluid is recycled back into the source stream, the present invention is environmentally friendly.
Other features and their advantages will be apparent to those skilled in the art from a careful reading of the Detailed Description of Preferred Embodiments accompanied by the following drawings.